/*******************************************************************************
 * Copyright 2006, 2017 Jerry Huxtable, Martin Davis
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * This file was semi-automatically converted from the public-domain USGS PROJ source.
 */
package org.locationtech.proj4j.proj;

import org.locationtech.proj4j.ProjCoordinate;

public class AugustProjection extends Projection {

	private final static double M = 1.333333333333333;

	public ProjCoordinate project(double lplam, double lpphi, ProjCoordinate out) {
		double t, c1, c, x1, x12, y1, y12;

		t = Math.tan(.5 * lpphi);
		c1 = Math.sqrt(1. - t * t);
		c = 1. + c1 * Math.cos(lplam *= .5);
		x1 = Math.sin(lplam) *  c1 / c;
		y1 =  t / c;
		out.x = M * x1 * (3. + (x12 = x1 * x1) - 3. * (y12 = y1 *  y1));
		out.y = M * y1 * (3. + 3. * x12 - y12);
		return out;
	}

	/**
	 * Returns true if this projection is conformal
	 */
	public boolean isConformal() {
		return true;
	}

	public boolean hasInverse() {
		return false;
	}

	public String toString() {
		return "August Epicycloidal";
	}

}
